Resilience improvement needs for public water supply systems in Dar Es Salaam
The impacts of natural hazards in the form of floods are severe, and lifeline systems such as water supply are at risk. Tanzania is no exclusion to this risk. A 30” water transmission main in Dar es Salaam was broken and dragged away following recent floods on 30th October 2017, while several other distribution pipes were also affected. The quality and quantity of water were compromised, while the alternative water sources are unreliable, due to salinity, and contamination from waste and flooding water.
This study was conducted to determine the on-ground and current resilience issues related to public water supply, and the needs for improvement. Questionnaire surveys to the residents of Vingunguti, Jangwani and Tandale wards, and interviews to DAWASCO, DAWASA, and Wami/Ruvu basin officials were conducted during the study. Standard descriptive and thematic approaches were used to analyse the questionnaires and interviews. The system experiences inadequate redundancy and lacks additional capacity to serve in case of shocks. Also, the system is suffering a severe loss (NRW) of about 50% and shows a high degree of interdependency to the National electric power grid. The natural vegetation in catchment and recharge areas have been affected by human activities while the water sources are also at risk of pollution and lack of continuous monitoring of the withdrawal and water balance. The impact of flooding seems significant to the water users, and the poor population is the most affected. Besides, the only significant alternative supply is buying, which is costly. The majority of the poor population are not prepared against floods.
The findings suggest that while improving technical aspects of the water supply system would address most social issues, environmental aspects showed the need for a separate assessment. Further work is needed to develop tools for measuring the resilience from which appropriate improvement measures will be determined.
This paper is a contribution to the 2019 edition of the Global Assessment Report on Disaster Risk Reduction (GAR 2019).
To cite this paper:
Sweya, L.N.; Wilkinson, S. and Kassenga, G. Resilience improvement needs for public water supply systems in Dar Es Salaam. Contributing Paper to GAR 2019